/*
* Copyright (c) 2000-2004, 2012-2025 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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* Please see the License for the specific language governing rights and
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*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*!
* @header kern_control.h
* This header defines an API to communicate between a kernel
* extension and a process outside of the kernel.
*/
#ifndef KPI_KERN_CONTROL_H
#define KPI_KERN_CONTROL_H
#include <sys/appleapiopts.h>
#include <sys/_types/_u_char.h>
#include <sys/_types/_u_int16_t.h>
#include <sys/_types/_u_int32_t.h>
#include <sys/_types/_u_int64_t.h>
/*
* Define Controller event subclass, and associated events.
* Subclass of KEV_SYSTEM_CLASS
*/
/*!
* @defined KEV_CTL_SUBCLASS
* @discussion The kernel event subclass for kernel control events.
*/
#define KEV_CTL_SUBCLASS 2
/*!
* @defined KEV_CTL_REGISTERED
* @discussion The event code indicating a new controller was
* registered. The data portion will contain a ctl_event_data.
*/
#define KEV_CTL_REGISTERED 1 /* a new controller appears */
/*!
* @defined KEV_CTL_DEREGISTERED
* @discussion The event code indicating a controller was unregistered.
* The data portion will contain a ctl_event_data.
*/
#define KEV_CTL_DEREGISTERED 2 /* a controller disappears */
/*!
* @struct ctl_event_data
* @discussion This structure is used for KEV_CTL_SUBCLASS kernel
* events.
* @field ctl_id The kernel control id.
* @field ctl_unit The kernel control unit.
*/
struct ctl_event_data {
u_int32_t ctl_id; /* Kernel Controller ID */
u_int32_t ctl_unit;
};
/*
* Controls destined to the Controller Manager.
*/
/*!
* @defined CTLIOCGCOUNT
* @discussion The CTLIOCGCOUNT ioctl can be used to determine the
* number of kernel controllers registered.
*/
#define CTLIOCGCOUNT _IOR('N', 2, int) /* get number of control structures registered */
/*!
* @defined CTLIOCGINFO
* @discussion The CTLIOCGINFO ioctl can be used to convert a kernel
* control name to a kernel control id.
*/
#define CTLIOCGINFO _IOWR('N', 3, struct ctl_info) /* get id from name */
/*!
* @defined MAX_KCTL_NAME
* @discussion Kernel control names must be no longer than
* MAX_KCTL_NAME.
*/
#define MAX_KCTL_NAME 96
/*
* Controls destined to the Controller Manager.
*/
/*!
* @struct ctl_info
* @discussion This structure is used with the CTLIOCGINFO ioctl to
* translate from a kernel control name to a control id.
* @field ctl_id The kernel control id, filled out upon return.
* @field ctl_name The kernel control name to find.
*/
struct ctl_info {
u_int32_t ctl_id; /* Kernel Controller ID */
char ctl_name[MAX_KCTL_NAME]; /* Kernel Controller Name (a C string) */
};
/*!
* @struct sockaddr_ctl
* @discussion The controller address structure is used to establish
* contact between a user client and a kernel controller. The
* sc_id/sc_unit uniquely identify each controller. sc_id is a
* unique identifier assigned to the controller. The identifier can
* be assigned by the system at registration time or be a 32-bit
* creator code obtained from Apple Computer. sc_unit is a unit
* number for this sc_id, and is privately used by the kernel
* controller to identify several instances of the controller.
* @field sc_len The length of the structure.
* @field sc_family AF_SYSTEM.
* @field ss_sysaddr AF_SYS_KERNCONTROL.
* @field sc_id Controller unique identifier.
* @field sc_unit Kernel controller private unit number.
* @field sc_reserved Reserved, must be set to zero.
*/
struct sockaddr_ctl {
u_char sc_len; /* depends on size of bundle ID string */
u_char sc_family; /* AF_SYSTEM */
u_int16_t ss_sysaddr; /* AF_SYS_KERNCONTROL */
u_int32_t sc_id; /* Controller unique identifier */
u_int32_t sc_unit; /* Developer private unit number */
u_int32_t sc_reserved[5];
};
#ifdef KERNEL
#include <sys/kpi_mbuf.h>
/*!
* @typedef kern_ctl_ref
* @discussion A control reference is used to track an attached kernel
* control. Registering a kernel control will create a kernel
* control reference. This reference is required for sending data
* or removing the kernel control. This reference will be passed to
* callbacks for that kernel control.
*/
typedef void * kern_ctl_ref;
/*!
* @defined CTL_FLAG_PRIVILEGED
* @discussion The CTL_FLAG_PRIVILEGED flag is passed in ctl_flags. If
* this flag is set, only privileged processes may attach to this
* kernel control.
*/
#define CTL_FLAG_PRIVILEGED 0x1
/*!
* @defined CTL_FLAG_REG_ID_UNIT
* @discussion The CTL_FLAG_REG_ID_UNIT flag is passed to indicate that
* the ctl_id specified should be used. If this flag is not
* present, a unique ctl_id will be dynamically assigned to your
* kernel control. The CTLIOCGINFO ioctl can be used by the client
* to find the dynamically assigned id based on the control name
* specified in ctl_name.
*/
#define CTL_FLAG_REG_ID_UNIT 0x2
/*!
* @defined CTL_FLAG_REG_SOCK_STREAM
* @discussion Use the CTL_FLAG_REG_SOCK_STREAM flag when client need to open
* socket of type SOCK_STREAM to communicate with the kernel control.
* By default kernel control sockets are of type SOCK_DGRAM.
*/
#define CTL_FLAG_REG_SOCK_STREAM 0x4
/* Data flags for controllers */
/*!
* @defined CTL_DATA_NOWAKEUP
* @discussion The CTL_DATA_NOWAKEUP flag can be used for the enqueue
* data and enqueue mbuf functions to indicate that the process
* should not be woken up yet. This is useful when you want to
* enqueue data using more than one call but only want to wake up
* the client after all of the data has been enqueued.
*/
#define CTL_DATA_NOWAKEUP 0x1
/*!
* @defined CTL_DATA_EOR
* @discussion The CTL_DATA_EOR flag can be used for the enqueue
* data and enqueue mbuf functions to mark the end of a record.
*/
#define CTL_DATA_EOR 0x2
__BEGIN_DECLS
/*!
* @typedef ctl_connect_func
* @discussion The ctl_connect_func is used to receive
* notification of a client connecting to the kernel control.
* @param kctlref The control ref for the kernel control the client is
* connecting to.
* @param sac The address used to connect to this control. The field sc_unit
* contains the unit number of the kernel control instance the client is
* connecting to. If CTL_FLAG_REG_ID_UNIT was set when the kernel control
* was registered, sc_unit is the ctl_unit of the kern_ctl_reg structure.
* If CTL_FLAG_REG_ID_UNIT was not set when the kernel control was
* registered, sc_unit is the dynamically allocated unit number of
* the new kernel control instance that is used for this connection.
* @param unitinfo A placeholder for a pointer to the optional user-defined
* private data associated with this kernel control instance. This
* opaque info will be provided to the user when the rest of the
* callback routines are executed. For example, it can be used
* to pass a pointer to an instance-specific data structure in
* order for the user to keep track of the states related to this
* kernel control instance.
*/
typedef errno_t (*ctl_connect_func)(kern_ctl_ref kctlref,
struct sockaddr_ctl *sac,
void **unitinfo);
/*!
* @typedef ctl_disconnect_func
* @discussion The ctl_disconnect_func is used to receive notification
* that a client has disconnected from the kernel control. This
* usually happens when the socket is closed. If this is the last
* socket attached to your kernel control, you may unregister your
* kernel control from this callback.
* @param kctlref The control ref for the kernel control instance the client has
* disconnected from.
* @param unit The unit number of the kernel control instance the client has
* disconnected from.
* @param unitinfo The user-defined private data initialized by the
* ctl_connect_func callback.
*/
typedef errno_t (*ctl_disconnect_func)(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo);
/*!
* @typedef ctl_send_func
* @discussion The ctl_send_func is used to receive data sent from
* the client to the kernel control.
* @param kctlref The control ref of the kernel control.
* @param unit The unit number of the kernel control instance the client has
* connected to.
* @param unitinfo The user-defined private data initialized by the
* ctl_connect_func callback.
* @param m The data sent by the client to the kernel control in an
* mbuf chain. Your function is responsible for releasing the
* mbuf chain.
* @param flags The flags specified by the client when calling
* send/sendto/sendmsg (MSG_OOB/MSG_DONTROUTE).
*/
typedef errno_t (*ctl_send_func)(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
mbuf_t m, int flags);
/*!
* @typedef ctl_setopt_func
* @discussion The ctl_setopt_func is used to handle set socket option
* calls for the SYSPROTO_CONTROL option level.
* @param kctlref The control ref of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param unitinfo The user-defined private data initialized by the
* ctl_connect_func callback.
* @param opt The socket option.
* @param data A pointer to the socket option data. The data has
* already been copied in to the kernel for you.
* @param len The length of the socket option data.
*/
typedef errno_t (*ctl_setopt_func)(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
int opt, void *data, size_t len);
/*!
* @typedef ctl_getopt_func
* @discussion The ctl_getopt_func is used to handle client get socket
* option requests for the SYSPROTO_CONTROL option level. A buffer
* is allocated for storage and passed to your function. The length
* of that buffer is also passed. Upon return, you should set *len
* to length of the buffer used. In some cases, data may be NULL.
* When this happens, *len should be set to the length you would
* have returned had data not been NULL. If the buffer is too small,
* return an error.
* @param kctlref The control ref of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param unitinfo The user-defined private data initialized by the
* ctl_connect_func callback.
* @param opt The socket option.
* @param data A buffer to copy the results in to. May be NULL, see
* discussion.
* @param len A pointer to the length of the buffer. This should be set
* to the length of the buffer used before returning.
*/
typedef errno_t (*ctl_getopt_func)(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
int opt, void *data, size_t *len);
#ifdef KERNEL_PRIVATE
/*
* KERN_CTL_REG_OPAQUE means that kern_ctl_reg is an opaque structure
* in the public header, and redeclared in kern_control_private.h.
*/
#define KERN_CTL_REG_OPAQUE
#endif /* KERNEL_PRIVATE */
#ifdef KERN_CTL_REG_OPAQUE
/*!
* @struct kern_ctl_reg
* @discussion This structure defines the properties of a kernel
* control being registered.
*/
struct kern_ctl_reg;
#else
/*!
* @struct kern_ctl_reg
* @discussion This structure defines the properties of a kernel
* control being registered.
* @field ctl_name A Bundle ID string of up to MAX_KCTL_NAME bytes (including the ending zero).
* This string should not be empty.
* @field ctl_id The control ID may be dynamically assigned or it can be a
* 32-bit creator code assigned by DTS.
* For a DTS assigned creator code the CTL_FLAG_REG_ID_UNIT flag must be set.
* For a dynamically assigned control ID, do not set the CTL_FLAG_REG_ID_UNIT flag.
* The value of the dynamically assigned control ID is set to this field
* when the registration succeeds.
* @field ctl_unit A separate unit number to register multiple units that
* share the same control ID with DTS assigned creator code when
* the CTL_FLAG_REG_ID_UNIT flag is set.
* This field is ignored for a dynamically assigned control ID.
* @field ctl_flags CTL_FLAG_PRIVILEGED and/or CTL_FLAG_REG_ID_UNIT.
* @field ctl_sendsize Override the default send size. If set to zero,
* the default send size will be used, and this default value
* is set to this field to be retrieved by the caller.
* @field ctl_recvsize Override the default receive size. If set to
* zero, the default receive size will be used, and this default value
* is set to this field to be retrieved by the caller.
* @field ctl_connect Specify the function to be called whenever a client
* connects to the kernel control. This field must be specified.
* @field ctl_disconnect Specify a function to be called whenever a
* client disconnects from the kernel control.
* @field ctl_send Specify a function to handle data send from the
* client to the kernel control.
* @field ctl_setopt Specify a function to handle set socket option
* operations for the kernel control.
* @field ctl_getopt Specify a function to handle get socket option
* operations for the kernel control.
*/
struct kern_ctl_reg {
/* control information */
char ctl_name[MAX_KCTL_NAME];
u_int32_t ctl_id;
u_int32_t ctl_unit;
/* control settings */
u_int32_t ctl_flags;
u_int32_t ctl_sendsize;
u_int32_t ctl_recvsize;
/* Dispatch functions */
ctl_connect_func ctl_connect;
ctl_disconnect_func ctl_disconnect;
ctl_send_func ctl_send;
ctl_setopt_func ctl_setopt;
ctl_getopt_func ctl_getopt;
};
#endif /* KERN_CTL_REG_OPAQUE */
/*!
* @function ctl_register
* @discussion Register a kernel control. This will enable clients to
* connect to the kernel control using a PF_SYSTEM socket.
* @param userkctl A structure defining the kernel control to be
* attached. The ctl_connect callback must be specified, the other callbacks
* are optional. If ctl_connect is set to zero, ctl_register fails with
* the error code EINVAL.
* @param kctlref Upon successful return, the kctlref will contain a
* reference to the attached kernel control. This reference is used
* to unregister the kernel control. This reference will also be
* passed in to the callbacks each time they are called.
* @result 0 - Kernel control was registered.
* EINVAL - The registration structure was not valid.
* ENOMEM - There was insufficient memory.
* EEXIST - A controller with that id/unit is already registered.
*/
errno_t
ctl_register(struct kern_ctl_reg *userkctl, kern_ctl_ref *kctlref);
/*!
* @function ctl_deregister
* @discussion Unregister a kernel control. A kernel extension must
* unregister it's kernel control(s) before unloading. If a kernel
* control has clients attached, this call will fail.
* @param kctlref The control reference of the control to unregister.
* @result 0 - Kernel control was unregistered.
* EINVAL - The kernel control reference was invalid.
* EBUSY - The kernel control has clients still attached.
*/
errno_t
ctl_deregister(kern_ctl_ref kctlref);
/*!
* @function ctl_enqueuedata
* @discussion Send data from the kernel control to the client.
* @param kctlref The control reference of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param data A pointer to the data to send.
* @param len The length of data to send.
* @param flags Send flags. CTL_DATA_NOWAKEUP and CTL_DATA_EOR are currently
* the only supported flags.
* @result 0 - Data was enqueued to be read by the client.
* EINVAL - Invalid parameters.
* EMSGSIZE - The buffer is too large.
* ENOBUFS - The queue is full or there are no free mbufs.
*/
errno_t
ctl_enqueuedata(kern_ctl_ref kctlref, u_int32_t unit, void *__sized_by(len) data,
size_t len, u_int32_t flags);
/*!
* @function ctl_enqueuembuf
* @discussion Send data stored in an mbuf chain from the kernel
* control to the client. The caller is responsible for freeing
* the mbuf chain if ctl_enqueuembuf returns an error.
* @param kctlref The control reference of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param m An mbuf chain containing the data to send to the client.
* @param flags Send flags. CTL_DATA_NOWAKEUP and CTL_DATA_EOR are currently
* the only supported flags.
* @result 0 - Data was enqueued to be read by the client.
* EINVAL - Invalid parameters.
* ENOBUFS - The queue is full.
*/
errno_t
ctl_enqueuembuf(kern_ctl_ref kctlref, u_int32_t unit, mbuf_t m, u_int32_t flags);
/*!
* @function ctl_getenqueuespace
* @discussion Retrieve the amount of space currently available for data to be sent
* from the kernel control to the client.
* @param kctlref The control reference of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param space The address where to return the current space available
* @result 0 - Success; the amount of space is returned to caller.
* EINVAL - Invalid parameters.
*/
errno_t
ctl_getenqueuespace(kern_ctl_ref kctlref, u_int32_t unit, size_t *space);
/*!
* @function ctl_getenqueuereadable
* @discussion Retrieve the difference between enqueued bytes and
* low-water mark for the socket receive buffer.
* @param kctlref The control reference of the kernel control.
* @param unit The unit number of the kernel control instance.
* @param difference The address at which to return the current difference
* between the low-water mark for the socket and the number of bytes
* enqueued. 0 indicates that the socket is readable by the client
* (the number of bytes in the buffer is above the low-water mark).
* @result 0 - Success; the difference is returned to caller.
* EINVAL - Invalid parameters.
*/
errno_t
ctl_getenqueuereadable(kern_ctl_ref kctlref, u_int32_t unit, u_int32_t *difference);
__END_DECLS
#endif /* KERNEL */
#if defined(PRIVATE) && !defined(MODULES_SUPPORTED)
#include <sys/kern_control_private.h>
#endif /* PRIVATE && !MODULES_SUPPORTED */
#endif /* KPI_KERN_CONTROL_H */